While there are paving contractors who own and operate cold planers, there are many who opt for subcontracting out that portion of their repaving contracts to a planer specialist. There are many reasons for this move. One is they do not tie up working capital or incur debt associated with the ownership of the equipment. Other reasons include the burden of getting enough paving projects requiring a planer and having a well-trained, experienced planer crew on the payroll. Operating cold planers is a specialty and requires specialists who can operate such equipment to achieve high-quality milling results both efficiently and safely.
Fortunately, there are contractors specializing in cold (pavement) planing who collectively perform this service nationwide. Nevertheless, as with any other special services contractors, their workmanship quality, services and expertise can vary. It behooves the paving contractor in need of planer services to ensure in advance that he is contracting with a planing contractor who can show a record of past satisfactory performance with other paving contractors.
Planer applications expert Don Pfeifer believes milling pavements with the precision required by most DOTs necessitates using a planing contractor who has cold planers featuring much of the latest technology and a planer crew which can carry out the milling process to meet the DOT’s specifications. Pfeifer is Donegal Construction Corp.’s vice president of operations, a company that specializes in cold planing.
Currently, the company owns and operates 34 cold planers with two locations—Greensburg, Pa., and under the company name Delta Contracting Inc. in Burlington, N.C. It recently sold its company in Florida, Delta Milling Inc., which additionally owned 12 cold planers.
The company serves 14 states from New York to Georgia to Alabama, Tennessee, Kentucky and Ohio. Sixty percent of the milling performed is for contractors who hold DOT and local government paving contracts with the balance of the contracts carried out in the private sector. Donegal is one of the, if not the, biggest cold planer contractors east of the Mississippi. It employs 165 people. Once strictly an excavation and site contractor, it started the cold planing business in 1989 with five profiling machines. This year, the company will add two more planers to the fleet bringing the number to 36.
Pfeifer said he is having Roadtec deliver a new-model Roadtec RX-700 cold planer this spring to have it demonstrated on some projects.
“We are evaluating the RX-700 for possibly buying two of them, but that depends on this new model’s performance. At present we own three different make milling machines and have bought each of them based on their merits,” said Pfeifer.
Small fits anything
Paving contractors have different requirements when it comes to the size planer they want to have used on their projects. For interstate milling projects, the high-horsepower units give the best performance. These machines are typically 700 to 1,000 hp and can meet the challenges of even the toughest milling projects.
One major drawback to these high-powered behemoths is just that, they are behemoths and not suitable for most streets in towns and urban settings. Their large footprint makes them unwieldy in tight areas thus reducing efficient milling productivity. Further, the extra-wide profiling machines are not suitable for highway shoulder work.
What Pfeifer needed was a compact planer powerful enough to handle most projects from city to interstate work.
“We needed these compact machines to meet the needs of some of our customers who take on town and city paving projects that require pavement milling. The key value of the Roadtec RX-500 is we can use them on mainline (highway) projects between the urban projects so they are constantly busy,” he said.
Here is an example of a highway application where the RX-500 fitted in efficiently working with an 800-hp planer. The paving project was on the Pennsylvania Turnpike. It called for milling 11?2-in. deep four 12-ft 6-in.-wide lanes that were each 17 miles long. The 800 took the lead by milling a 7-ft-wide pass, followed by the RX-500 completing milling the lane with a 5-ft 6-in.-wide pass. Each planer progressed at a rate of up to 120 ft per minute, giving good results.
Fast milling rates up to 120 ft per minute are possible with the latest cold planers. They can advance at the higher rates and still produce smooth surface results because some planer manufacturers have increased the revolving cutting drum’s rpm. For instance, Roadtec increased the rpm on its new-model planers to a maximum of 93 as opposed to the older models’ 70 rpm.
Another plus for using a compact planer is the ease in its transport as compared to its big brothers. To illustrate, the RX-500’s transport-ready weight is 58,000 lb while the Roadtec RX-900 (Roadtec’s flagship) weight is 82,000 lb. Highway permits are simpler to get and the costs are less for the smaller planer. As to footprints, the RX-500 overall dimensions are, including the conveyor, 45 ft 8 in. x 7 ft 8 in., while the 900 is 55 ft 1 in. x 9 ft. Head clearances for the main bodies are 8 ft 6 in. and 10 ft 7 in., respectively.
There are, however, some tradeoffs in using small- to medium-hp planers. For example, the RX-900 can mill up to 12 ft 6 in. wide in a single pass while the RX-500’s maximum planing width is 7 ft 2 in. For nonstop major highway projects, the larger-capacity planer is the ideal. It requires only one pass to mill one lane where it would take two smaller planers and two crews to maintain the same productivity. All of this said, Pfeifer said he has encountered no appreciable problems in substituting two 7-ft-wide-capacity planers in lieu of one jumbo. Further, there is the advantage of using the RX-500 as the selection of various cutter mandrels that range from 2 ft to 7 ft. The varied widths are suitable for making narrow cuts and for road shoulders. Interchanges and limited highway ramps are much more suited for using an RX-500 than the big RX-900.
For the moment, Pfeifer does not intend to add a jumbo planer such as the RX-900 to the fleet. Nevertheless, he said that such a machine might be in the future, depending on the paving contractors’ requirements on interstate highway projects. Meanwhile the mix of planers in the fleet can satisfy the requirements of all their paving contractors.
Watch your spacing
Donegal not only offers the paving contractor different-size planers to match their projects’ requirements but the cutter mandrels are available either in 5?16 in. or in the standard 5?8 in. spacings. Chris McSharry, the vice president of new technology at Roadtec, said there are two favorable results associated when milling with 5?16 in. spacings. One is the vehicular ride is smoother than riding over a pavement that was milled with 5?8-in. spacings. This is particularly important if the milled paving is not to be immediately overlaid but opened for traffic flow. A major safety item is driving motorcycles over milled paving. Many motorcyclists attest that driving over a 5?8 in. spaced can cause them to lose control of their bikes, according to Pfeifer. This is not so when driving over 5?16-in.-spaced paving. The smooth-ride result is further experienced if a “thin wear coat” (? 1 in.) is applied over the milled paving. The reason is there is a less pronounced reflecting because of the tighter groove spacings.
Planing isn’t always simple
For paving contractors who intend to subcontract out the planing part of their contracts there are four important factors that should be considered before evaluating the subcontractor’s bid price:
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Does he have a planer of the right size for your project so it will not impede the paving process?;
Is the planer in good working condition? If there are unscheduled breakdowns, it could have serious effects on the overall productivity of the paving process;
Does the subcontractor supply a well-trained planer crew for ensuring not only optimum production but also safety on the job?; and
Will the subcontractor’s crew and equipment be on your project in a timely fashion, thus ensuring no wait time?
As already discussed in depth, Donegal has a fleet of planers that can match most any project efficiently. As to equipment readiness, all of the company’s planers are completely overhauled during the winter months to ensure minimum unscheduled downtime on the milling projects. No matter how well designed and well built a planer is, it can be a liability on a paving project if the crew is not well trained and experienced. Donegal holds training and refresher courses each spring for all crews, and all must attend these seminars, no matter how experienced an individual is.
“Our company continues to grow because we have the right people; we give the contractor just-in-time service and we offer the best and most reliable equipment available,” he said.
